Four cars of an E train equipped with state-of-the-art security cameras made its unprecedented first run this morning, part of an aggressive anti-terror and crime initiative that the MTA could expand to every line in the subway system.

Riders in the super-secure cars will see a sticker that reads: “Notice: This train may be equipped with a video recording device.”

The train will make four runs today — from Jamaica Center to the World Trade Center –two in the morning hours and two in the afternoon.

The cameras won’t be watched live, but will be digitally taped and stored and used in investigations and criminal prosecutions.

Also installed in the same cars are “fold-up” subway seats, which transit officials may use in the future to squeeze 18 percent more riders into subway cars during rush hour.

Vertical bars on those cars will be closer to the windows, instead of pushed toward the center. Also, metal grasps — hearkening back to the hanging straps — will be placed on the cross-bar above the seats.

There’s no timeline when the seats will be “unlocked” and put into use.

As for the cameras, transit officials said alerting riders to their mere presence can reduce crime and aid in fighting terror.

“Video camera systems have clearly been shown to help deter criminal activity on transit vehicles,” said new subway and bus chief Thomas Prendergast.

He added that the cameras are invaluable when it comes to investigating the “potential threat of terrorist activity” on the subway.

If a straphanger is assaulted — heaven forbid — he or she can report the incident to the NYPD and police can then use the video feed in the investigation.

Each car will be equipped with four cameras, for a total of 16. The system was manufactured and installed by California-based TOA Corp. with little to no cost to the MTA.

“The cameras will be conspicuously installed in the train,” said a NYCT source. “It’ll provide us with forensic evidence.”

There will be a 12-month evaluation process, and then a final decision on their use will be made in 2011.

Officials will look at video quality and after “evaluation of the system, NYC Transit may consider implementing the closed-circuit television system throughout the subway fleet,” said Steven Feil, senior vice president for the department of subways.

Straphangers welcomed the watchful eye, saying criminals were less likely to strike if they know they’re being recorded.

“It’ll protect people. It’ll bring down a lot of unwanted activities on the train,” said Donald Terrell, 48, from Harlem.

“A lot of people in New York see something but they don’t say anything,” he added.

Several female riders said the cameras will give them peace of mind during late-night commutes.

“There are a lot of perverts out there, and if cops aren’t around now you’ll be able to say “run the tape!” said Nicole Davis, 34, a Bronx school bus driver.

MTA board member Norman Seabrook, who chairs the safety and security committee, said he was concerned about people “vandalizing” the cameras.